Installation Instructions for the
ISSUE 3
Hall-Effect Position Sensors
SR3 and SR4 Series
PK 87863
Sensing and Control
GENERAL INFORMATION
Completely sealed in threaded plastic bushings to
meet NEMA 3, 3R, 3S, 4, 4X, 12 and 13
requirements.
24 gage stranded leadwires with irradiated
Polyethelene insulation.
ELECTRICAL AND MAGNETIC CHARACTERISTICS
SR3F-A1 SR3B-A1 SR3G-A1 SR3C-A1 SR4P2-A1 (4)
Electrical
Supply voltage, VDC 4.5 to 24 4.5 to 24 4.5 to 24 4.5 to 24 6 to 24
Supply current, mA max. 18.0 15.0 22.0 19.0 13.5
Output type NPN (Sink) NPN (Sink) NPN (Sink) NPN (Sink) NPN (Sink)
Output voltage, V max. 0.40 0.40 0.40 0.40 0.40
Output current, mA max. 10 10 10 10 20
Magnetic
Magnetic Type Unipolar (1) Bipolar (2) Unipolar (1) Unipolar (1) Omnipolar (3)
-40 to +85°C (4)
Max. Operate 450 150 430 190 25
(-40 to +185°F)
Min. Release 170 -150 160 60 5
Min. Differential 20 40 50 10 20
+25°C (+77°F)
Typ. Operate 400 90 350 150 15
Typ. Release 185 -90 280 100 11
Typ. Differential 20 80 70 30 4
1. A unipolar sensor has a plus maximum operate point and a plus minimum release point. One magnetic pole (south) is
required to operate and release a unipolar sensor.
2. A bipolar sensor has a plus (south pole) maximum operate point and a minus (noth pole) minimum release point.
Operate and release points can be both positive or both negative. Latching cannot be guaranteed. Ring magnets
are usually used with bipolar sensors.
3. An omnipolar sensor operates with any magnetic field (north or south pole).
4. SR4P2-A1 operating characteristics are over -20 to +85°C (-4 to +185°F).
ABSOLUTE MAXIMUM RATINGS*
Parameters 4.5 to 24 VDC 6.0 to 24 VDC
Supply voltage (V) -0.5 to +28 VDC -1.2 to +24 VDC
Voltage externally
applied to output
+26 VDC max.
(OFF only)
+24 VDC max.
(OFF only)
-0.5 VDC min.
(ON or OFF)
-0.5 VDC max.
(ON or OFF)
Output current 20 mA 20 mA
Temperature
Operate & Storage
-40 to +85°C
(-40 to +185°F)
-20 to +85°C
(-4 to +185°F)
Magnetic flux No limit. Circuit cannot be damaged
by magnetic overdrive.
* Absolute maximum ratings are the extreme limits that
the device will withstand without damage to the device.
However, the electrical and mechanical characteristics
are not guaranteed as the maximum limits (above
recommended operating conditions) are approached,
nor will the device necessarily operate at absolute
maximum ratings.
NOTICE
Do not reverse supply voltage polarity.
Do not exceed maximum ratings.
Torque on plastic nuts must not exceed 12 inch
pounds (1,356 Nm).
TROUBLESHOOTING
If sensor does not operate, follow these steps.
1. Check wiring. Load must be connected.
2. Measure supply voltage across Red (+) and
Black (-) leads to verify proper voltage presence.
3. Connect positive voltmeter lead to Green
(output), negative voltmeter lead to Black
(ground). Remove magnet (or present north
pole). Reading should equal Vs.
4. Move magnet (or south pole) toward sensing face
(beyond operating point). Output should change
state. Voltage should be 0.40 VDC maximum.